This article describes the development of an instrument to audit the nurse-patient relationship based on the nursing philosophy of a Swiss hospital, which describes the nurse-patient relationship using terms such as mutual respect, support, accompaniment and information. Members of the nursing department developed quality criteria for the nurse-patient relationship employing the Nominal Group Technique. The criteria were validated through a review of the relevant literature. In a next step the criteria were operationalized into a normative instrument for evaluating the nurse-patient relationship. Using this instrument data was gathered in five wards both by interviewing patients and nurses and by analysing nursing documents. Data analyses revealed different levels in the quality indicators in the various wards. These differences can be explained on one hand by differences in the quality of the nurse-patient relationship on these wards and on the other hand by errors in the instrument. Suggestions on how to raise validity and reliability of the instrument are stated.